Oracle Forms/Java tutorial
How to build a
new Javabean
1. Purpose
The purpose of this tutorial is to
demonstrate how to build and integrate a new JavaBean in an Oracle Forms
application.
2. The goal
In this tutorial we are going to develop a JavBean that retrieved the
background color of a Forms canvas.
But, why not simply use the Get_Canvas_Property( ‘canvas_name’, BACKGROUND_COLOR ) built-in ?
The reason why we cannot use the Forms GET_Canvas_Property built-in is
that it returns null if the background color is not explicitly set.
The trick to solve this problem ithus s to use a Forms bean area item
and locate in on the Forms canvas. The background color property is then read
from JavaBean container’s parent container.
3. Build the bean
·
Open Jdeveloper
·
Create a new application
Right click on the Applications node then click the New
Application option
·
Enter the name of the new
application
·
Enter the name of the new
project
·
Add a new class to the
project
Right click on the OracleFormsBean node and click the New Java
Class option
·
Set the name of the class and
the name of the package
In this sample, the class name is GetCanvasProp and the package
name is oracle.forms.fd
A Javabean source code ‘s skeleton (bean_template.txt) is provided with
the samples to help you to quickly start a new PJC/Javabean class.
·
Open the bean_template.txt
file provided with the samples, then copy the content in the new
GetCanvasProp.java window
Some of he imported classes are Forms specific and are not available in
JDeveloper by default. You need to add these classes by creating a custom
library in JDeveloper that points to the f90all.far file located in the
<ORACLE_HOME>/forms90/java/ directory (versions 9.0.2 and 9.0.4) or in
the <ORACLE_HOME>/forms/java/ directory (version 10.1.2), where It is
named to frmall.jar.
·
Copy this file and paste it
in the /lib sub-directory of your
Jdeveloper installation path.
·
Right-click on the OracleFormsBean
project node then click the Project Properties option.
·
In the Libraries tab,
click the Add Jar/Directory button.
·
Select the f90all.jar
file (version 9.0.2, 9.0.4) or the frmall.jar file (version 10.1.2).
Ok, so this is the java code, now:
package oracle.forms.demo;
import oracle.forms.handler.IHandler;
import oracle.forms.ui.CustomEvent;
import oracle.forms.properties.ID;
import oracle.forms.ui.VBean;
public class my_new_class
extends VBean
{
static
IHandler mHandler;
// properties you can set
protected
static final ID SET_01 = ID.registerProperty("SET_01");
protected
static final ID SET_02 = ID.registerProperty("SET_02");
// properties you can be get
protected
static final ID GET_01 = ID.registerProperty("GET_01");
// events you can raise
protected
static final ID EVT_01 = ID.registerProperty("EVT_01");
// default constructor
public my_new_class()
{
super();
}
public void
init(IHandler handler)
{
super.init(handler);
mHandler
= handler;
// put your initialisation instructions here
}
/**
*
Set the properties to the bean
**/
public
boolean setProperty(ID property, Object value)
{
if(property
== SET_01)
{
System.out.println("Set property 01=" + (String)value) ;
// add your code here
return
true;
}
else if
(property == SET_01)
{
// add your code here
return
true;
}
else // default behaviour
{
return super.setProperty(property, value);
}
}
/**
*
Get the properties of the bean
**/
public Object
getProperty(ID property)
{
if
(property == GET_01)
{
// return the corresponding value
return
"the property needed" ;
}
else // default behaviour
{
return
super.getProperty(property);
}
}
/**
*
Send a message to the Forms module
**/
public void
dispatch_event( ID id )
{
CustomEvent ce = new CustomEvent(mHandler, id);
dispatchCustomEvent(ce);
}
}
The parts displayed with a bold red font
are those you have to adapt.
·
Adapt the correct name of the
bean (replace the my_new_class occurences with the name of your real class.
·
Adapt the properties IDs to
give them a more comprehensive sense.
Get a particular property
In our sample we want to get the background color of the canvas, so a
good name for the corresponding property ID could be : GETBGCOLOR
You get the bean property from the Forms module through the getProperty()
method wich is part of the Vbean class.
All what we need is to get the background color of the parent’s
component
This is the code of the getProperty() function:
if
(property == GETBGCOLOR)
{
// get the color of the parent container
String
sColor="" ;
Color
color = this.getParent().getBackground() ;
sColor =
"r"+ color.getRed() +"g"+color.getGreen()+"b"+
color.getBlue() ;
// return the value
return
sColor ;
}
Set a particular property
We also want to hide/show the Java Bean component, so we need to set its
“visible” property.
This is done in the setProperty() method, trough the SETHIDDEN
property ID.
The setProperty() method takes 2 arguments :
The property ID and an object that contains the value. (this value comes
from the 4th argument of the Forms built-in Set_Custom_Property).
This is the code of the setProperty() function:
if(property
== SETHIDDEN) // Hide/Show the Java Bean component
{
// get the parameter string
String
sParam = (String)value ;
if(
sParam.equals("true") )
setVisible(false);
else
setVisible(true);
return
true;
}
Then, the java code should, now, look like this:
(modified parts appear in a bold font)
package oracle.forms.demo;
import java.awt.Color;
import oracle.forms.handler.IHandler;
import oracle.forms.ui.CustomEvent;
import oracle.forms.properties.ID;
import oracle.forms.ui.VBean;
public class GetCanvasProp extends VBean
{
static
IHandler mHandler;
// properties you can set
protected
static final ID SETHIDDEN =
ID.registerProperty("SETHIDDEN");
// properties you can be get
protected
static final ID GETBGCOLOR =
ID.registerProperty("GETBGCOLOR");
// events you can raise
protected static
final ID EVT_01 =
ID.registerProperty("EVT_01");
// default constructor
public
GetCanvasProp()
{
super();
}
public void
init(IHandler handler)
{
super.init(handler);
mHandler
= handler;
// put your initialisation instructions here
}
/**
*
Set the properties to the bean
**/
public
boolean setProperty(ID property, Object value)
{
if(property
== SETHIDDEN) // Hide/Show the Java Bean component
{
// get the parameter string
String
sParam = (String)value ;
if(
sParam.equals("true") )
setVisible(false);
else
setVisible(true);
return
true;
}
else // default behaviour
{
return
super.setProperty(property, value);
}
}
/**
*
Get the properties of the bean
**/
public Object
getProperty(ID property)
{
if
(property == GETBGCOLOR)
{
// get the color of the parent container
String
sColor="" ;
Color
color = this.getParent().getBackground() ;
sColor =
"r"+ color.getRed() +"g"+color.getGreen()+"b"+
color.getBlue() ;
// return the value
return
sColor ;
}
else // default behaviour
{
return super.getProperty(property);
}
}
/**
*
Send a message to the Forms module
**/
public void
dispatch_event( ID id )
{
CustomEvent ce = new CustomEvent(mHandler, id);
dispatchCustomEvent(ce);
}
}
So, at this moment we need to deploy the .jar file to integrate it with
the Forms application.
·
Add a new Deployement Profile to the project that
allows to generate and deploy the corresponding .jar file of the new javabean.
Right-click the OracleFormsBean project node then click the New
option
·
Select the Deployment
Profiles tab then the JAR File option
·
Choose a name for this
Deployment profile
·
Set the path where the .jar
file will be copied at each deployment (I use to indicate the /forms/java
directory)
Then deploy the .jar file.
·
Right-click the FormsProperties.deploy
node then click the Deploy to JAR file option.
Be sure the .jar file is well deployed in the /forms/java directory.
If not, copy manually the .jar file into the forms/java directory.
4. Setup the Forms configuration file : formsweb.cfg
This file is located in your <ORACLE_HOME>/forms/server
directory.
·
Open this file and search for
the archive_jini tag
·
Add your .jar file to this
tag.
·
archive_jini=frmall_jinit.jar,...,FormsProperties.jar
·
save the formsweb.cfg file.
5. Build the Forms test dialog
·
Open the Forms Builder
·
Create a new canvas
·
Add a javabean item on the
new canvas
·
Set its Implementation Class
property to : oracle.forms.demo.GetCanvasProp
(remember the package and class name of your bean)
From now on you are able to set and get the properties of your javabean.
Set a property
To set a property of your javabean, use the Set_Custom_Property()
built-in
Set_Custom_Property( ‘item_name’, record_number,
‘property_name’, ‘property_value’ ) ;
On the When-Button-Pressed trigger, we set this property with the
following code:
Set_Custom_Property( 'BL.BEAN_AREA', 1, 'SETHIDDEN',
'true' ) ;
or
Set_Custom_Property( 'BL.BEAN_AREA', 1, 'SETHIDDEN',
'false ) ;
Get a property
To get a property from your javabean, use the Get_Custom_Property()
built-in
Varchar2 := Get_Custom_Property( ‘item_name’,
record_number, ‘property_name’ ) ;
item_name is
the name of the bean area item that support the Java Implementation Class.
In our sample, we want to get the background color through the
GETBGCOLOR property ID, so the call to the built-in is the following:
BColor := Get_Custom_Property( 'BL1.BEAN_AREA', 1,
'GETBGCOLOR' ) ;
6. The sample dialog
Open the BEAN.fmb dialog provided with the zip file.
Compile and run it.
This is the code executed in the When-New-Form-Instance
trigger:
Declare
FColor Varchar2(30) ;
BColor Varchar2(30) ;
Begin
-- Get the Forms property --
FColor :=
Get_Canvas_Property( 'CV1', BACKGROUND_COLOR ) ;
:BL.EL1 :=
'[' || FColor || ']' ;
-- Get the Javabean property --
BColor :=
Get_Custom_Property( 'BL.BEAN_AREA', 1, 'GETBGCOLOR' ) ;
:BL.EL2 :=
'[' || BColor || ']' ;
If BColor
is not null Then
Set_Item_Property( 'BL.PUSH_BUTTON2',
BACKGROUND_COLOR, BColor ) ;
End if ;
End;
As you can see, the Get_Canvas_Property() built-in returns a NULL
value, whereas the Get_Custom_Property() returns the correct value.
(my current colorscheme is BLAF at this very moment)
The Hide bean push button allows to hide/show the bean item.
You may get, of course, another value if you use a different
colorscheme.
1. Forms and Java version
In order to run your javabean in the Forms application, you have to
verify that the Compiler option of the Jdeveloper product is setted to 1.3